Electrostatic chucks are widely used to hold substrates, such as semiconductor wafers, during substrate processing in processing chambers used for various applications, such as physical vapor deposition, etching, or chemical vapor deposition. Electrostatic chucks typically include one or more electrodes embedded within a unitary chuck body which includes a dielectric or semi-conductive ceramic material across which an electrostatic clamping field can be generated.
Electrostatic chucks offer several advantages over mechanical clamping devices and vacuum chucks. For example, electrostatic chucks reduce stress-induced cracks caused by mechanical clamping, allow larger areas of the substrate to be exposed for processing (little or no edge exclusion), and can be used in low pressure or high vacuum environments. Additionally, the electrostatic chuck can hold the substrate more uniformly to a chucking surface to allow a greater degree of control over substrate temperature.
Various processes used in the fabrication of integrated circuits may call for high temperatures and/or wide temperature ranges for substrate processing. For example, electrostatic chucks in etch processes typically operate in a temperature range of up to about 120° C. At temperatures above about 120° C., the components of many electrostatic chucks will begin to fail due to various issues such as de-chucking in Al2O3 electrostatic chucks, plasma erosion from corrosive chemistry, bond reliability, and so on.